There is increasing demand for magnetic components, such as inductors and transformers, with improvements such as decreased weight, height, or volume for given values of electrical parameters, such as inductance, AC and DC resistance, and quality factor and having lower losses, lower leakage inductance, and better balancing of interwinding capacitance and leakage inductance. One technology where this demand is significant is electric and hybrid automobiles.
Magnetic components have traditionally been made by winding wires, machining, and metal cutting. Metal cutting techniques that have been used include stamping, chemical etching, plasma cutting, milling, and electrical discharge machining (EDM). Each of these cutting methods has at least one of the following disadvantages when considered for mass production of improved components as described above: (1) high retooling costs following design changes; (2) relatively large kerf (the width of material removed during cutting); (3) inability to cut relatively thick metal; (4) relatively slow cutting speeds; (5) tool wear; (6) thermal and mechanical stress of the conductor; and (7) need for highly trained machine operators.